Tissue Oximetry Probe with Tissue Marking Feature

ABSTRACT

An intraoperative tissue oximetry device includes a tissue marker that includes one or more pens or one or more similar ink sources, such that the tissue marker can mark tissue according to oxygen saturation measurements made by the tissue oximetry device, thereby visually delineating regions of potentially viable tissue from regions of potentially nonviable tissue.

BACKGROUND OF THE INVENTION

This patent application claims the benefit of U.S. provisional patentapplications 61/642,389, 61/642,393, 61/642,395, and 61/642,399, filedMay 3, 2012, and 61/682,146, filed Aug. 10, 2012, which are incorporatedby reference along with all other references cited in this application.

BACKGROUND OF THE INVENTION

The present invention relates generally to optical systems that monitoroxygen levels in tissue. More specifically, the present inventionrelates to an optical probe that includes light sources, detectors, anda marking apparatus for marking local tissue regions that are probed bythe optical probe.

Oximeters are medical devices used to measure oxygen saturation oftissue in humans and living things for various purposes. For example,oximeters are used for medical and diagnostic purposes in hospitals andother medical facilities (e.g., surgery, patient monitoring, orambulance or other mobile monitoring, such as for hypoxia); sports andathletics purposes at a sports arena (e.g., professional athletemonitoring); personal or at-home monitoring of individuals (e.g.,general health monitoring, or personal training, such as for amarathon); and veterinary purposes (e.g., animal monitoring).

In particular, assessing a patient's oxygenation state is important asit is an indicator of the state of the patient's health. Thus, oximetersare often used in clinical settings, such as during surgery andrecovery, where it may be suspected that the patient's tissueoxygenation state is unstable. For example, in reconstruction surgeries,it is desirable to distinguish between tissue that is viable andnon-viable to save as much viable tissue as possible. Via the use ofoximeters, physicians can attempt to distinguish between viable andnon-viable tissue. However, physicians typically have to remember a mapof viable tissue and non-viable tissue, which may slow down medicalprocedures.

Pulse oximeters and tissue oximeters are two types of oximeters thatoperate on different principles. A pulse oximeter requires a pulse inorder to function. A pulse oximeter typically measures the absorbance oflight due to pulsing arterial blood. In contrast, a tissue oximeter doesnot require a pulse in order to function, and can be used to make oxygensaturation measurements of a tissue flap that has been disconnected froma blood supply.

Human tissue, as an example, includes a variety of molecules that caninteract with light via scattering or absorption (e.g., vialight-absorbing chromophores). Such chromophores include oxygenated anddeoxygenated hemoglobins, melanin, water, lipid, and cytochrome.Oxygenated and deoxygenated hemoglobins are the most dominantchromophores in the spectrum range of 600 nanometers to 900 nanometers.Light absorption differs significantly for oxygenated and deoxygenatedhemoglobins at certain wavelengths of light. Tissue oximeters canmeasure oxygen levels in human tissue by exploiting theselight-absorption differences.

Despite the success of existing oximeters, there is a continuing desireto improve oximeters by, for example, improving measurement accuracy;reducing measurement time; lowering cost; reducing size, weight, or formfactor; reducing power consumption; and for other reasons, and anycombination of these.

Therefore, there is a need for oximeters that have improved form factorsand that relieve physicians and medical personal of having to rememberof map of tissue scanned by an oximeter.

BRIEF SUMMARY OF THE INVENTION

An intraoperative tissue oximetry device includes a pen or pens orsimilar ink source (or sources) such that tissue can be marked accordingto oxygenation measurements made by the tissue oximetry device, therebyvisually delineating regions of potentially viable tissue from regionsof potentially nonviable tissue.

According to an embodiment, the device is a handheld, self-contained,oximeter device. The oximeter probe is contained within a single housingincluding all the components, so that it is self-contained. No externalconnections via wires or wireless connectivity are needed. The probe hasa compact size and is relatively light weight so that it can be heldeasily by a person's hand. The probe can include a handle for a person'shand to grip, or fingers to grip.

The probe includes a plurality of light sources configured to generateand emit light into a portion of an extended tissue region, and aplurality of detectors having a circular arrangement and configured todetect the light subsequent to reflection from the portion and generatereflectance data based on detection of the light. The handheld,self-contained, oximeter further includes a processor configured todetermine the oxygen saturation of the portion based on the reflectancedata, and includes a tissue marker. The tissue marker includes adispenser that is located at substantially a center of a circle of thecircular arrangement where the dispenser is configured to deposit inkonto the portion to indicate that the probe has probed the portion.

According to a specific embodiment, the dispenser is configured todeposit ink based on one or more ranges of the oxygen saturation. Theprocessor may be configured to determine whether the oxygen saturationis in the one or more ranges and control the dispenser to deposit theink based on the one or more ranges that the oxygen saturation is in.

According to a specific embodiment, the dispenser is configured todeposit a plurality of colors of ink; the processor is configured tocontrol the tissue marker to deposit the colors of ink based on rangesof the oxygen saturation; and the ranges of the oxygen saturation arerespectively associated with the colors of the ink. The processor may beconfigured to control the tissue marker to deposit the ink onto theportion, or alternatively, a user selection device, such as a switch, isconfigured to be activated by a user to control the tissue marker todeposit the ink.

According to another embodiment, a handheld, self-contained, oximeterincludes a probe that in-turn includes: (i) a plurality of light sourcesconfigured to generate and emit light into a portion of an extendedtissue region, and (ii) a plurality of detectors that has a circulararrangement and is configured to detect the light subsequent toreflection from the portion and generate reflectance data based ondetection of the light. The handheld, self-contained, oximeter furtherincludes a processor configured to determine oxygen saturation of theportion based on the reflectance data. The handheld, self-contained,oximeter further includes a tissue marker having a plurality ofdispensers. The dispensers are located outside of a circle of thecircular arrangement and are configured to deposit ink onto the portionto indicate that the portion has been probed by the probe.

According to one embodiment, a method of operation of a handheld,self-contained oximeter includes emitting light into tissue, detectingthe light subsequent to reflection of the light from the tissue, andgenerating reflectance data based on detecting the light. The methodfurther includes determining an oxygen saturation of the tissue based onthe reflectance data, and determining a range of oxygen saturation froma plurality of ranges of oxygen saturation in which the oxygensaturation lies. The method includes marking the tissue with ink basedon the range that the oxygen saturation is in.

Oximeter embodiments of the present invention are capable of accuratelymeasuring oxygenation saturation of tissue and marking regions of thetissue to indicate their viability or nonviability. Relatively quicklyand easily determining viability from the markings is useful for aplastic surgeon, for example, where in intraoperative situations theplastic surgeon must quickly make determinations to distinguish betweentissue that can be used for reconstruction and tissue that should beremoved.

With the incorporation of the tissue marker, the tissue oximetry devicemay be used to fully examine multiple regions of tissue for viabilityprior to the creation of further surgical incisions or the removal orreconstruction of tissue. The tissue marker of the present inventionallows for relatively precisely marking regions of tissue based on theiroxygen saturation readings thus alleviating physicians from having torecall exactly which tissue may be considered viable based onoxygenation measurements once the physician has set aside the tissueoximetry device or has moved the tissue oximetry device to other tissueregions.

In an implementation, an oximeter probe is contained within a singlehousing. The oximeter probe includes: a number of light or radiationsources, positioned on a probe face of the housing, configured togenerate and emit light or radiation into a portion of an extendedtissue region; a number of detectors, positioned on the probe face,wherein the detectors are positioned in a circular arrangement andconfigured to detect the light subsequent to reflection from theportion; a processor, connected to the light sources and detectors,configured to process reflectance data received from the detectors anddetermine oxygen saturation of the portion based on the reflectancedata; a battery power source, contained within the housing and connectedto the light sources, detectors, and processor; and a tissue markingcomponent having a dispenser or inking tip or head, connected to theprobe face, where the dispenser is located within the circulararrangement (e.g., inside the circle) and is configured to deposit inkonto the portion, thereby indicating that the portion has been evaluatedby the probe.

In another implementation, a method of operating an oximeter probeincludes: emitting light into tissue from radiation sources positionedon a probe face of the oximeter probe housing; detecting the lightsubsequent to reflection of the light from the tissue using fromdetectors sources positioned on a probe face of an oximeter probehousing; generating reflectance data based on detecting the light by wayof a processor contained with the oximeter probe housing; using theprocessor (e.g., without needing to use an external processor),determining an oxygen saturation of the tissue based on the reflectancedata; using the processor, determining a range of oxygen saturation froma plurality of ranges of oxygen saturation in which the oxygensaturation lies; and marking the tissue with ink (or other fluid) basedon the range in which the oxygen saturation is in using ink (or otherfluid) stored in a reservoir contained within the oximeter probe housingand a inking tip positioned on the probe face.

Other objects, features, and advantages of the present invention willbecome apparent upon consideration of the following detailed descriptionand the accompanying drawings, in which like reference designationsrepresent like features throughout the figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B show a simplified perspective view and a top view,respectively, of a tissue oximetry device according to one embodiment.

FIG. 1C shows a block diagram of the tissue oximetry device.

FIG. 2A shows a simplified end view of a tissue oximetry probe of thetissue oximetry device according to one embodiment where the inkdispenser is centered on the tissue oximetry probe.

FIG. 2B shows a simplified end view of the tissue oximetry probe wherefirst and second dispensers are located outside of a circle ofdetectors.

FIG. 3 shows a high-level flow diagram of a method for marking tissue toindicate ranges of oxygen saturation of the tissue.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates generally to a tissue oximetry device formeasuring oxygen saturation in a local tissue volume. More specifically,the present invention relates to a wireless, handheld, tissue oximetrydevice that has self-contained optics (lights sources and detectors),computer processing, a display, a power-supply, and a tissue marker formarking tissue as the tissue is probed by the self-contained optics.

FIGS. 1A and 1B are a simplified perspective view and a top view,respectively, of a tissue oximetry device 100 according to oneembodiment. The figures show an enclosure or housing of an oximeterprobe device. Tissue oximetry device 100 is configured to make tissueoximetry measurements, such as intraoperatively and postoperatively.

In an implementation, the tissue oximetry device is handheld device andcan make tissue oximetry measurements and display these measurements,without needing to connect to another external component either via acable or wirelessly. The electronics to make measurements andcalculations is contained entirely within the housing of the tissueoximetry device. The device may be a standalone handheld tissue oximetrydevice, without a cable or wireless connection.

Tissue oximetry device 100 may be a handheld device that includes atissue oximetry probe 115 (also referred to as a sensor head), which maybe positioned at an end of a sensing arm 114. Tissue oximetry device 100is configured to measure the oxygen saturation of tissue by emittinglight, such as red and near-infrared light, from tissue oximetry probe115 into tissue, and collecting light reflected from the tissue at thetissue oximetry probe.

Tissue oximetry device 100 may include a display 112 or othernotification device (e.g., a speaker for audible notification) thatnotifies a user of oxygen saturation values measured by the tissueoximetry device. While tissue oximetry probe 115 is described as beingconfigured for use with tissue oximetry device 100, which is a handhelddevice, tissue oximetry probe 115 may be used with other tissue oximetrydevices, such as a modular tissue oximetry device where the tissueoximetry probe is at the end of a cable device that couples to a baseunit. The cable device might be a disposable device that is configuredfor use with a single patient and the base unit might be a device thatis configured for repeated use. Such modular tissue oximetry devices arewell understood by those of skill in the art and are not describedfurther.

Tissue oximetry device 100 does not require a pulsing blood flow to makean oxygen saturation measurement as compared with pulse oximeters thatrequire a pulsing blood flow to make such measurements. While thedescription of the example embodiments is directed toward tissueoximetry probes that do not require a pulsing blood flow for oxygensaturation measurements, embodiments of the present invention are not solimited and may be utilized with pulse oximeters.

FIG. 1C is a block diagram that shows tissue oximetry device 100 infurther detail according to one embodiment. The components of device 100are contained in a single enclosure or housing. Tissue oximetry device100 may include display 112, a processor 116, a memory 117, a speaker118 (described briefly above), one or more input devices 119 (e.g., oneor more switches, input buttons, keypad, display 112, if for example,the display is a touch screen, or the like), a set of light sources 120,a set of detectors 125, a power source 127, and a tissue marker 130.Processor 116 may be a microcontroller, a microprocessor, control logic,a multicore processor, or the like, and may control the operation oflight sources 120 and detectors 125. Processor 116 may also control theoperation of tissue marker 130. Memory 117 may include a variety ofmemories, such as a volatile memory 117 a (e.g., a RAM), a nonvolatilememory 117 (e.g., a disk, Flash, PROM, or others), or both. User inputmay be by way of the input devices 119 (e.g., switches, touchpad, or thelike).

Power source 127 can be a battery, such as a disposable battery.Disposable batteries are discarded after their stored charge isexpended. Some disposable battery chemistry technologies includealkaline, zinc carbon, or silver oxide. The battery has sufficientstored charged to allow use of the tissue oximetry device for severalhours. After use, the tissue oximetry device is discarded.

In other implementations, the battery can also be rechargeable where thebattery can be recharged multiple times after the stored charge isexpended. Some rechargeable battery chemistry technologies includenickel cadmium (NiCd), nickel metal hydride (NiMH), lithium ion(Li-ion), and zinc air. The battery can be recharged, for example, viaan AC adapter with cord that connects to the handheld unit. Thecircuitry in the tissue oximetry device can include a recharger circuit(not shown). Batteries with rechargeable battery chemistry may besometimes used as disposable batteries, where the batteries are notrecharged but disposed of after use.

Aspects of the invention may include software executable code orfirmware (e.g., code stored in a read only memory or ROM chip). Thesoftware executable code or firmware may embody algorithms used inmaking oxygen saturation measurements of the tissue. The softwareexecutable code or firmware may include code to implement a userinterface by which a user uses the system, displays results on thedisplay, and selects or specifies parameters that affect the operationof the system.

The components may be linked together via a bus 128, which may be thesystem bus architecture of tissue oximetry device 100. Although thisfigure shows one bus that connects to each component, the busing isillustrative of any interconnection scheme serving to link thesecomponents or other components included in tissue oximetry device 100.For example, speaker 118, according to one specific implementation,could be connected to a subsystem through a port or have an internaldirect connection to processor 116.

The foregoing listed components may be housed in a mobile housing (seeFIG. 1A) of tissue oximetry device 100. However, differentimplementations of tissue oximetry device 100 may include alternativehousing (such as the cables and the base units of modular oximetersdescribed briefly above) and may include any number of the listedcomponents, in any combination or configuration, and may also includeother components not shown.

Tissue Oximetry Probe

FIG. 2A is a simplified end view of tissue oximetry probe 115 accordingto one embodiment. Tissue oximetry probe 115 is configured to contacttissue (e.g., a patient's skin) for which a tissue oximetry measurementis to be made. Tissue oximetry probe 115 includes the set of lightsources 120 and the set of detectors 125. The set of light sources 120may include two or more light sources, such as light sources 120 a and120 b.

Light sources 120 may be linearly positioned across tissue oximetryprobe 115 and detectors 125 may be arranged in an arc or a circle (i.e.,circular arrangement) on the tissue oximetry probe. More specifically,light sources 120 may be arranged linearly, such as on a line (e.g., adiameter) that bisects a circle on which detectors 125 may be arranged.The light sources 120 a and 120 b are spaced a distance D1 apart whereD1 may range from about 3 millimeters to about 10 millimeters. That is,the circle on which detectors 125 are arranged may have a diameter ofabout 3 millimeters to about 10 millimeters (e.g., 4 millimetersaccording to one specific embodiment). While detectors 125 are describedas being arranged in an arc or circle, tissue oximetry device 100 mayhave other configurations of detectors, such as linear, square,rectangular, ovoid, pseudo-random, or others.

Propagation depth increases with increasing source-to-detector distance,with 4-5 millimeters generally being a sufficient upper limit betweenlight sources 120 a and detectors 125 to ensure few detected photonspropagated in lower tissue layers. For example, these distances betweenlight sources 120 and detectors 125 limits reflectance data to lightthat propagated within the top layer of tissue where little or nounderlying subcutaneous fat or muscular layers contributes to thereflectance data.

The set of detectors 125 may include four or more detectors. Accordingto a specific embodiment, the set of detectors 125 includes eightdetectors 125 a, 125 b, 125 c, 125 d, 125 e, 125 f, 125 g, and 125 h asshown. Detectors 125 are solid-state detectors and may be mounted to aPCB (not shown). Further, detectors 125 may be combined devices ordiscrete devices.

In a specific implementation, detectors 125 are positioned with respectto outer light sources 120 a and 120 c such that four or more (e.g.,fourteen) unique source-to-detector distances are created. With greaternumbers of source-to-detector distances, this can be used to obtaingreater accuracy, faster calibration, and redundancy (when duplicatesource-to-detector distances are provided). At least twosource-to-detectors distances are 1.5 millimeters or closer, and atleast two more two source-to-detectors distances are 2.5 millimeters orfarther.

In other words, a first source-to-detector distance is about 1.5millimeters or less. A second source-to-detector distance is about 1.5millimeters or less. A third source-to-detector distance is about 2.5millimeters or greater. A fourth source-to-detector distance is about2.5 millimeters or greater. There can be various numbers of sources anddetector arrangements to obtain these four source-to-detector distances,such as one source and four detectors, two sources and two detectors,one detector and four sources, or other arrangements and combinations.

For example, an implementation includes at least two sources and atleast two detectors, where a maximum distance between a source and adetector is about 4 millimeters (or about 5 millimeters). At least twosource-to-detector are about 2.5 millimeters or greater. At least twosource-to-detector distances are about 1.5 millimeters or less.

When a greater number of sources and detectors are used, greater numbersof source-to-detector distances are available. As discussed, these canbe used to provide greater accuracy, faster calibration, or redundancy,or a combination. The arrangement of the sources and detectors can be incircular pattern, such as at points along the arc of a circle withradius (e.g., 4 millimeters, or 5 millimeters). In an implementation, atolerance of the detector or source positions on the arc is within 10microns of the arc curve. In other implementations, the tolerance iswithin about 0.25 millimeters.

Tissue Marking

Turning now to tissue marker 130, tissue oximetry probe 115 includes atleast a dispenser portion of tissue marker 130. FIG. 2 shows an end viewof the dispenser that can dispense a marking material on a local tissueregion (e.g., of an extended portion of tissue) that has been probed bytissue oximetry device 100. The location of the marking material ontissue allows a user to subsequently identify the particular, localtissue region that has been probed.

The dispenser may be located at a variety positions on the face oftissue oximetry probe 115. According to one specific embodiment, thedispenser is located between light sources 120 a and 120 b, and may belocated at the approximate center of the circular arrangement ofdetectors 125. With the dispenser at the approximate center of lightsources 120 and detectors 125, a mark made by the dispenser will besubstantially at a center of the local tissue region that has beenprobed by tissue oximetry device 100. With the mark at the center of theprobed tissue region, the mark is not displaced from the location on thelocal tissue region probed.

According to one implementation, tissue marker 130 includes one or moredispensers that may be located at different positions on the head oftissue oximetry probe 115. FIG. 2B shows an embodiment where twodispensers are located “outside” of light sources 120 and detectors 125.That is, the dispensers are located at the ends of radii that are longerthan the radii of light sources 120 and detectors 125. Further, thedispensers may lie on a line that passes through the center of thecircle of the circular arrangement of dispensers 125. With thedispensers located along such a line, marks made by these dispensersallow a user to readily identify the region between the marks as thelocal tissue region that has been probed by tissue oximetry device 100.

While the dispensers shown in FIGS. 2A and 2B are shown as relativelylocalized devices (e.g., pen, pens, inker, inkers, and the like) thatmay be configured to mark tissue with relatively small marks (e.g.,dots), a dispenser may be an extended device configured to make anextended mark, such as a line. For example, a dispenser may be anextended device configured to mark tissue with a circle or other closedshape, or may mark tissue with an open shape, such as a u-shape, av-shape, or others.

The dispenser may be fixed within tissue oximetry probe 115 or may beconfigured to be lowered when tissue is marked. Various mechanical orelectromechanical devices may be utilized by tissue oximetry probe 115for lowering the dispenser. Such mechanical and electro-mechanicaldevices are well understood by those of skill in the art and are notdescribed in detail herein.

Tissue marker 130 may mark tissue with a variety inks having a varietyof colors, such as gentian violet, which is the tissue marking inkapproved by the FDA. Variations in the gentian violet chemistryconstituents can give different characteristics to the ink and causechanges in color or shade. Any of these colors or shades of gentianviolet may be utilized by tissue marker 130.

One or more of the ink colors utilized by tissue oximetry device 100 mayindicate one or more oxygen saturation ranges. For example, tissuemarker 130 might be configured to: (i) mark tissue with a first color ofink if the tissue's oxygen saturation is at or below a first threshold,(ii) mark the tissue with a second color of ink if the tissue's oxygensaturation is above the first threshold and at or below a secondthreshold, and (iii) mark the tissue with a third color of ink if thetissue's oxygen saturation is above the second threshold. The foregoingexample describes the use of three colors of ink for marking tissue forvisually identifying three ranges of oxygen saturation, however more orfewer colors may be utilized by tissue marker 130 for identifying moreor fewer oxygen saturation ranges.

Processor 116 may determine the oxygen saturation of a local tissueregion based on an analysis of the reflection data that has beengenerated by detectors 125, and may control tissue marker 130 to markthe local tissue region with a select color of ink that identifies therange that the oxygen saturation is within. Tissue marker 130 mayinclude a variety of devices that provide marking material having one ormore colors, such as ink reservoirs, pens, or the like. U.S. patentapplication Ser. No. 12/178,359, filed Jul. 23, 2008, of Heaton, titled“Oximeter with Marking Feature”, which is incorporated by reference inits entirety, describes a variety of devices that are configured formarking tissue with one or more colors of marking material.

A reservoir of the marking device can be connected to the dispenser,such as through tubing or channels, and is contains ink or other fluid(e.g., ink) dispensed through the dispenser. Ink can be urged from thereservoir to and through the dispenser and deposited on skin throughpressure or low-frequency sound (such using a piezoelectric transducer).The reservoir is contained within the same housing as the processor,battery, sources, detectors, and other components of the oximeter probe.For the disposable probe, the reservoir is not refillable.

According to one alternative, tissue marker 130, under control ofprocessor 116, marks tissue for one or more oxygen saturation ranges,but does not mark the tissue for one or more other oxygen saturationregions. For example, tissue marker 130 might mark a local tissue regionif the oxygen saturation of the local tissue region is at or below athreshold level, or alternatively might not mark the local tissue regionif the oxygen saturation level is above the threshold level. Markingsthat are made on tissue according to the above method allow a user torelatively quickly identify tissue that might have a low chance ofviability if the threshold level is relatively low. Alternatively,tissue marker 130 might mark a local tissue region if the oxygensaturation of the local tissue region is at or above a threshold level,and might not mark the local tissue region if the oxygen saturationlevel is below the threshold level. Marks made from this method allow auser to relatively quickly identify tissue that might have a relativelyhigh chance of viability if the threshold level is relatively high.

Information for the foregoing described threshold levels (i.e., ranges)may be stored in memory 117 and accessed by processor 116 for use. Thethreshold levels may be stored in memory 117 during manufacture oftissue oximetry device 100, or may be stored in the memory thereafter.For example, tissue oximetry device 100 may be configured to receive auser input for one or more user defined threshold levels and storeinformation for these threshold levels in memory 117. One or more inputdevices 119 (or the like) may be configured to receive a user input fora user defined threshold level and for storing the user definedthreshold level in memory 117.

FIG. 3 is a high-level flow diagram of a method for marking tissue toindicate ranges of oxygen saturation of the tissue. The high-level flowdiagram represents one example embodiment. Steps may be added to,removed from, or combined in the high-level flow diagram withoutdeviating from the scope of the embodiment.

At 300, tissue oximetry probe 115 contacts the tissue. Light (e.g.,near-infrared light) is emitted from one or more of the light sources120, step 305, into the tissue and at least some of the light isreflected back by the tissue. Each detector 125 receives a portion ofthe light reflected from the tissue, step 310, and each detectorgenerates reflectance data (i.e., a response) for the portion ofreflected light received, step 315. At 320, processor 305 determines anoxygen saturation value for the tissue based on the reflectance data. At325, processor 116 determines a range of oxygen saturation from aplurality of ranges of oxygen saturation in which the oxygen saturationlies. At 330, processor 116 controls tissue marker 130 to mark thetissue with ink based on a range in which the oxygen saturation is in.For example, the processor may be configured to control the dispenser tomark the tissue with ink if the oxygen saturation is in a first range ofoxygen saturation, but not mark the tissue if the oxygen saturation in asecond range of oxygen saturation where the first range and second rangeare different, such as not overlapping ranges. While the foregoingexample embodiment, discusses the utilization of two ranges of oxygensaturation by the tissue oximetry device, the tissue oximetry device mayutilize more than two ranges of oxygen saturation for determiningwhether to mark the tissue with ink.

According to one embodiment, the processor may control the dispenser tomark the tissue with a specific color of ink based on the range ofoxygen saturation that the oxygen saturation is in. The particular colorof ink allows a user to relatively quickly determine the ranges ofoxygen saturation for the tissue without the need for re-probing thetissue or looking at a chart of the tissue that includes oxygensaturation values and matching the chart to the tissue.

Tissue oximetry device 100 may be configured to allow a user to manuallycontrol the tissue oximetry device to mark tissue, allow processor 116to control marking the tissue, or both. For example, one of inputdevices 119 may be configured to control tissue marker 130 to mark alocal tissue region if a user activates the input device. The inputdevice may be conveniently located for a user to operate tissue oximetrydevice 100 to make an oxygen saturation measurement, and operate theinput device without moving tissue oximetry probe 115 from the localtissue region that was probed.

Tissue oximetry device 100 may be switched between the processorcontrolled method of marking tissue and the manually controlled method(e.g., activating one of the switches) of marking tissue. One or moreother of input devices 119 may be configured for switching tissueoximetry device 100 between these two methods of marking tissue.

This description of the invention has been presented for the purposes ofillustration and description. It is not intended to be exhaustive or tolimit the invention to the precise form described, and manymodifications and variations are possible in light of the teachingabove. The embodiments were chosen and described in order to bestexplain the principles of the invention and its practical applications.This description will enable others skilled in the art to best utilizeand practice the invention in various embodiments and with variousmodifications as are suited to a particular use. The scope of theinvention is defined by the following claims.

The invention claimed is:
 1. A device comprising: an oximeter probecontained within a single housing comprising: a plurality of lightsources, coupled to a probe face of the housing, configured to generateand emit light into a portion of an extended tissue region; a pluralityof detectors, coupled to the probe face, wherein the detectors arepositioned in a circular arrangement and configured to detect the lightsubsequent to reflection from the portion; a processor, coupled to thelight sources and detectors, configured to process reflectance datareceived from the detectors and determine oxygen saturation of theportion based on the reflectance data; a battery power source, containedwithin the housing and coupled to the light sources, detectors, andprocessor; and a tissue marking component having a dispenser, coupled tothe probe face, wherein the dispenser is located within the circulararrangement and is configured to deposit ink onto the portion, therebyindicating that the portion has been evaluated by the probe.
 2. Thedevice of claim 1 comprising a notification device configured to providea notification of the oxygen saturation.
 3. The device of claim 1wherein the dispenser is configured to deposit ink based on one or moreranges of the oxygen saturation.
 4. The device of claim 3 wherein theprocessor is configured to determine whether the oxygen saturation is inthe one or more ranges and control the dispenser to deposit the inkbased on the one or more ranges that the oxygen saturation is in.
 5. Thedevice of claim 1 wherein the dispenser is configured to deposit aplurality of colors of ink, the processor is configured to control thetissue marker to deposit the colors of ink based on ranges of the oxygensaturation, and the ranges of the oxygen saturation are respectivelyassociated with the colors of the ink.
 6. The device of claim 5 whereinthe ranges of the oxygen saturation are user programmable.
 7. The deviceof claim 1 wherein the processor is configured to control the tissuemarker to deposit the ink onto the portion.
 8. The device of claim 7comprising: a user selection device configured to be activated by auser, wherein the user selection device is configured to enable anddisable the processor for controlling the tissue marker for depositingthe ink.
 9. The device of claim 1 comprising: a user selection deviceconfigured to be activated by a user, wherein activation of the userselection device controls the tissue marker to deposit the ink onto theportion.
 10. The device of claim 1 comprising: a user selection deviceconfigured to initiate movement of the dispenser from a first positionto a second position in the probe, wherein in the second position thedispenser is configured to deposit the ink onto the portion.
 11. Thedevice of claim 10 wherein the processor is configured to initiatemovement of the dispenser from the first position to the second positionsubsequent to an oxygen saturation measurement.
 12. A device comprising:an oximeter probe contained within a single housing comprising: aplurality of light sources configured to generate and emit light into aportion of an extended tissue region; a plurality of detectors having acircular arrangement and configured to detect the light subsequent toreflection from the portion and generate reflectance data based ondetection of the light; a processor configured to determine oxygensaturation of the portion based on the reflectance data; and a tissuemarker having a plurality of dispensers, wherein the dispensers arelocated outside of a circle of the circular arrangement and areconfigured to deposit ink onto the portion to indicate that the portionhas been probed by the probe.
 13. The device of claim 12 wherein thedispensers are configured to deposit ink based on one or more ranges ofthe oxygen saturation.
 14. The device of claim 13 wherein the processoris configured to determine whether the oxygen saturation is in the oneor more ranges and control the dispensers to deposit the ink based onthe one or more ranges that the oxygen saturation is in.
 15. The deviceof claim 12 comprising a notification device configured to provide anotification of the oxygen saturation.
 16. The device of claim 12wherein the dispenser is configured to deposit a plurality of colors ofink, the processor is configured to control the tissue marker to depositthe colors of ink based on ranges of the oxygen saturation, and theranges of the oxygen saturation are respectively associated with thecolors of the ink.
 17. The device of claim 12 wherein the ranges of theoxygen saturation are user programmable.
 18. The device of claim 12further comprising a memory configured to store information for theranges.
 19. The device of claim 12 wherein the processor is configuredto control the tissue marker to deposit the ink onto the portion. 20.The device of claim 19 comprising a user selection device configured tobe activated by a user, wherein the user selection device is configuredto enable and disable the processor for controlling the tissue markerfor depositing the ink.
 21. The device of claim 12 comprising a userselection device configured to be activated by a user, whereinactivation of the user selection device controls the tissue marker todeposit the ink onto the portion.
 22. The device of claim 12 comprisinga user selection device configured to initiate movement of the dispenserfrom a first position to a second position in the probe, wherein in thesecond position the dispenser is configured to deposit the ink onto theportion.
 23. The device of claim 22 wherein the processor is configuredto initiate movement of the dispenser from the first position to thesecond position subsequent to an oxygen saturation measurement.
 24. Amethod of operating an oximeter probe comprising: emitting light intotissue from radiation sources positioned on a probe face of the oximeterprobe housing; detecting the light subsequent to reflection of the lightfrom the tissue using from detectors sources positioned on a probe faceof the oximeter probe housing; generating reflectance data based ondetecting the light by way of a processor contained with the oximeterprobe housing; using the processor, determining an oxygen saturation ofthe tissue based on the reflectance data; using the processor,determining a range of oxygen saturation from a plurality of ranges ofoxygen saturation in which the oxygen saturation lies; and marking thetissue with ink based on the range in which the oxygen saturation is inusing ink stored in a reservoir contained within the oximeter probehousing and a inking tip positioned on the probe face.